Systems and methods for determining the configuration of electronic connections

ABSTRACT

Systems and methods for determining the configuration of a connection between two devices by measuring an electrical characteristic are provided. Using the measured electrical characteristic, a device is able to select an appropriate communication interface, such as serial, Universal Serial Bus (USB), FireWire, parallel, PS/2, etc., and configure itself appropriately. Systems and methods which determine the physical orientation of a connector with respect to another connector may also be provided alone or in combination with such systems and methods for selecting communication interfaces. The physical orientation of a connector can be determined by measuring an electrical characteristic and a device can then configure itself appropriately. In accordance with the principles of the present invention, device designs can decrease in size and cost as well as simplify operation for the end-user.

BACKGROUND OF THE INVENTION

The present invention relates to electronic connections. Moreparticularly, the present invention relates to systems and methods fordetermining the configuration of electronic connections.

Many devices are capable of communicating with other devices through theuse of more than one communication interface. For example, a computeruses different interfaces for communicating with a monitor, a keyboard,and other computers on a network. In the case of a computer, eachinterface usually has its own, dedicated connector. However in somedevices, for example portable electronics, it may be advantageous tohave one connector that is capable of communicating using more than onetype of interface.

This is particularly true as portable electronic devices become smaller,because the physical size and number of connectors becomes an importantfactor. The size of connector contacts cannot get much smaller due tomanufacturing and power transmission issues. Therefore, engineers try toreduce the number of connectors by incorporating the signals needed foreach different interface into a single connector. This typically resultsin a larger connector with redundant contacts that are only used forcertain interfaces.

Thus, it would be advantageous to be able to use individual connectorcontacts for more than one interface. The more contacts that havemultiple functions, the smaller the connector can be. In order for acontact to carry more than one type of signal, a device must be able toidentify the interface being used and route the signal appropriately.

Many connectors and their housings are designed so that they can only becoupled in a certain configuration. This design process is commonlyreferred to as “keying” a connector and can include, for example, usingasymmetrical connector shapes. Connectors are typically designed thisway so that it is impossible to connect the wrong contacts. This can beespecially important when dealing with sensitive electronics that couldbe damaged by the application of a power supply line to the wrongcontact. Often, the design of the connectors prevents them from beingcoupled in an incorrect orientation.

Coupling these types of connectors can be time-consuming for users. Ifconnectors cannot be mated on the first try, users have to manipulatethe connectors until they are correctly orientated with respect to eachother. Depending on the keying, there may even be potential for the userto damage the pins of the connector in frustration while trying to forcethe connectors together. If a connector's pin configuration could besensed and properly compensated for, connectors could be coupled in morethan one orientation, thereby simplifying the process for an end user.Therefore, it is desirable to provide systems and methods fordetermining a connector's orientation. Further, it is also desirable tocombine systems and methods for selecting a communication interface withthose for determining a connector's orientation.

Further limitations and disadvantages of conventional and traditionalapproaches will become apparent to one of skill in the art, throughcomparison of such systems with some aspects of the present invention asset forth in the remainder of the present application with reference tothe drawings.

SUMMARY OF THE INVENTION

Systems and methods for determining the configuration of electronicconnections by measuring an electrical characteristic of a connectionare provided. Using the measured electrical characteristic, a device isable to select an appropriate communication interface, such as serial,Universal Serial Bus (USB), FireWire, parallel, PS/2, etc. Once theappropriate communication interface has been selected, the device cansubsequently configure itself to communicate using the selectedinterface. In accordance with the principles of the present invention,one connector can facilitate communication using multiple interfaces.This could allow a device with a single connector to communicate withmultiple types of devices. This one-connector approach saves both spaceand money, as well as making the act of mating two connectors easier forthe end user.

Systems and methods which determine the physical orientation of aconnector may also be provided alone or in combination with such systemsand methods for selecting communication interfaces. In accordance withthe principles of the present invention, symmetrical connectors withmultiple mating configurations can be used. A device can determine theorientation of a connector relative to another connector and properlyroute the signals from a connector according to the detectedorientation. This type of design can save the end user time andfrustration when coupling connectors together.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention, its nature, andvarious advantages will be more apparent upon consideration of thefollowing detailed description, taken in conjunction with theaccompanying drawings.

FIG. 1 is a simplified schematic system diagram of an embodiment of asystem which can be operated in accordance with the principles of thepresent invention, wherein a switch is used to route signals topredetermined locations.

FIG. 2 is a simplified schematic system diagram of an embodiment of asystem which can be operated in accordance with the principles of thepresent invention, wherein one or more signals are generated to indicatethe interface;

FIG. 3 is a simplified schematic system diagram of an embodiment of asystem which can be operated in accordance with the principles of thepresent invention, wherein signals are routed to circuits correspondingto each interface;

FIG. 4 is a simplified schematic system diagram of an embodiment of asystem which can be operated in accordance with the principles of thepresent invention, wherein the orientation of a two-wire connector isdetermined;

FIG. 5 is a simplified schematic system diagram of another embodiment ofa system which can be operated in accordance with the principles of thepresent invention, wherein the orientation of a three-wire connector isdetermined;

FIG. 6 is a simplified schematic system diagram of an embodiment of asystem which can be operated in accordance with the principles of thepresent invention, wherein the orientation of a four-wire connector isdetermined;

FIG. 7 is a simplified schematic system diagram of an embodiment of asystem which can be operated in accordance with the principles of thepresent invention, wherein the connector orientation is determined and acommunication interface is selected;

FIG. 8 is a simplified diagram of different voltage ranges that could beused to determine physical orientations and select communicationinterfaces in accordance with the principles of the present invention.

FIG. 9 is a flowchart of a method for selecting communication interfacesin accordance with the principles of the present invention;

FIG. 10 is a flowchart of a method for determining connectororientations in accordance with the principles of the present invention;and

FIG. 11 is a flowchart of a method for determining connectororientations and selecting communication interfaces in accordance withthe principles of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Many electronic communication interfaces exist. Devices communicateusing, for example, parallel, serial, PS/2, Universal Serial Bus (USB),and FireWire interfaces. Devices which communicate over more than oneinterface typically have a separate connector for each interface. Inorder for a connector to facilitate communication using more than onetype of interface, a system which selects appropriate communicationinterfaces can be used.

FIG. 1 includes an embodiment of a system 100 operable to selectcommunication interfaces in accordance with the principles of thepresent invention. System 100 can include device 110 and device 120.Device 110 can be an electronic device operable to communicate withother electronic devices using an interface. Device 120 can be anelectronic device operable to select the communication interface whichdevice 110 is using and then communicate with device 110 using theselected interface. Device 120 can, for example, be operable tocommunicate using a Universal Serial Bus (USB) interface as well as anRS-232 serial interface.

Devices 110 and 120 can be coupled by, for example, lines 110 a and 110b as well as data bus 110 c. Line 110 a can carry a supply voltage(V_(BUS)). Line 110 b can carry a ground (GND) associated with supplyvoltage 110 a. Data bus (DATA) 110 c can include one or more lines thatcarry data to be exchanged between devices 110 and 120. DATA 110 c canalso include lines which carry transmission information, for exampletiming and control signals, which is pertinent to the communicationinterface being utilized. Lines which are part of the coupling betweendevice 110 and 120 can also transmit other signals. Lines 110 a, 110 b,and 110 c can be bound together in a cable or harness that couplesdevices 110 and 120. The coupling hardware can be a separate piece ofequipment which may be detached from devices 110 and 120. Alternatively,the coupling hardware can be part of device 110 or device 120. Device110 can, for example, plug into a socket on device 120.

Device 120 can include connector 121 to provide a physical connection oflines 110 a, 110 b, and 110 c between device 110 and device 120.Connector 121 can include an electrical contact for each line connectingdevice 110 with device 120. Connector 121 can be, for example, a socketfor receiving a plug. Connector 121 can be shaped to ensure that onlydevices with a complementary shape can be coupled to device 120.Connector 121 can include a conductive connector shell. The connectorshell can be tied to, or replace, ground line 110 b or circuit ground ofdevice 120. Connector 121 can include a magnetic element to secure theconnection between devices 110 and 120 in such a way that, if the wirerunning to device 110 is pulled, the connector simply detaches.

Device 120 can include detector 122. Detector 122 can be coupled to oneor more of the lines that are part of the connection between devices 110and 120 (e.g. V_(BUS) 110 a, GND 110 b, DATA 110 c). Detector 122 canbe, for example, a distributed circuit, an Application-SpecificIntegrated Circuit (ASIC), or a Field-Programmable Gate Array (FPGA).Detector 122 can have additional functions, for example signalconditioning or power regulation. Detector 122 does not have to becoupled with every line connected between device 110 and device 120.

Detector 122 can be operable to measure one or more electricalcharacteristic of the connection between devices 110 and 120. Theelectrical characteristic measured by detector 122 can include, forexample, a resistive, reactive, current, or voltage measurement and caninvolve one or more contacts. Detector 122 can, for example, measure thevoltage of V_(BUS) 110 a relative to GND 110 b. Alternatively, detector122 can detect the resistance between a line of DATA bus 110 c and GND110 b. In another embodiment, detector 122 can be coupled with thesystem clock of device 120 and can monitor the behavior of DATA 110 cwith respect to the system clock. It is contemplated that there areseveral different characteristics or combinations of characteristicsthat can be measured by detector 122 in order to select the appropriatecommunication interface.

In one embodiment, device 110 might be a device that uses a USBinterface or a device that uses a low-voltage serial interface. Ifdetector 122 can measure, for example, the voltage of V_(BUS) 110 arelative to GND 110 b, detector 122 can select if device 110 is using aUSB interface or a low-voltage serial interface. Because the USBstandard calls for a power supply line with a voltage of 4.35V to 5.25V,a higher voltage would indicate a USB interface and a lower voltage, forexample below 3V, would indicate a low-voltage serial interface.

Device 120 can include switches 125 a and 125 b. The inputs of switch125 a can be coupled with V_(BUS) 110 a and GND 110 b. The inputs ofswitch 125 b can be coupled with DATA 110 c and other lines that arepart of the connection between devices 110 and 120. Switches 125 a and125 b can be in an open state by default. If switches 125 a and 125 bare in an open state by default, detector 122 can better measurecharacteristics of lines 110 a-110 c without any effects due to circuitsin device 120.

From one or more measured characteristic, detector 122 can be operableto select the communication interface being used by device 110. Switches125 a and 125 b can be controlled by detector 122 through aconfiguration signal (CONF) 123. Detector 122 can direct switch 125 a toclose once detector 122 has selected which communication interfacedevice 110 is using. Detector 122 can direct switch 125 b to move to astate corresponding to the selected communication interface. Becauseswitches 125 a and 125 b are controlled by a signal from detector 122,switches 125 a and 125 b can also be referred to as relays.

Device 120 can include voltage regulator 126. Voltage regulator 126 canbe coupled to the outputs of switch 125 a so that when switch 125 a isclosed, voltage regulator 126 is connected to V_(BUS) 110 a and GND 110b. Voltage regulator 126 can, for example, include circuitry operable tocharge a battery in device 110 from a power supply in device 120. Inanother embodiment, voltage regulator 126 can directly couple V_(BUS)110 a with the voltage rail of device 120 and GND 110 b with the commonground of device 120.

Device 120 can include processor 127. Processor 127 can be, for example,a microcontroller or an ARM processor. Processor 127 can be coupled withthe system clock of device 120. Processor 127 can be capable ofcommunicating over more than one interface. Processor 127 can havedifferent input/output busses 127 a and 127 b for communicating overdifferent interfaces. Processor 127 can be coupled to the outputs ofswitch 125 b. The first outputs of switch 125 b can be coupled to onebus (DATA1) 127 a of processor 127 that corresponds to a particularinterface. The second outputs of switch 125 b can be coupled to a secondbus (DATA2) 127 b of processor 127 that corresponds to a differentinterface. Switch 125 b can connect DATA 110 c with DATA1 127 a or DATA2127 b in order to facilitate communication using the detected interface.Processor 127 can proceed to communicate with device 110 using thisinterface. Processor 127 can also perform other functions which areinherent to device 120. Processor 127 can, for example, access flashmemory and process audio signals.

FIG. 2 includes an embodiment of a system 200 operable to select acommunication interface in accordance with the principles of the presentinvention. System 200 can include device 210 and device 220. Device 220can include a detector 222. From one or more measured characteristic,detector 222 can be operable to select the communication interface beingused by device 210. Other characteristics of device 210 can beidentified by detector 222. For example, detector 222 can determine thecharge-level of a battery within device 210.

Detector 222 can generate an interface select signal (INT_SEL) 224 whichcan indicate the interface that corresponds with the measuredcharacteristic. INT_SEL 224 can include one or more lines and cantransmit other information about device 210. For example, INT_SEL 224can also transmit a low power warning or a device identification number.

Device 220 can include switch 225. Switch 225 can toggle V_(BUS) 210 a,GND 210 b, DATA 210 c, and other lines that are part of the connectionbetween devices 210 and 220 between an open and closed state. Switch 225can be in an open state by default. Switch 225 can be controlled bydetector 222 through an enable signal (EN) 223. Detector 222 can directswitch 225 to close once detector 222 has selected which communicationinterface device 210 is using.

Device 220 can include a voltage regulator 226. Voltage regulator 226can be coupled to switch 225 so that, when switch 225 is in a closedposition, V_(BUS) 210 a and GND 210 b can be connected to voltageregulator 226.

Device 220 can include processor 227. Processor 227 can be coupled withthe system clock of device 220. Processor 227 can be coupled to switch225 so that when the switch is closed DATA 210 c is connected to acommunication bus (DATA) 227 b of processor 227. Processor 227 canmonitor INT_SEL 224 to see what communication interface device 210 usesand configure itself or other circuitry accordingly. Processor 227 canconfigure itself by loading a set of instructions that correspond to acommunication interface used by device 210.

DATA bus 227 b of processor 227 can be designed so that each differentinterface uses all of the lines that make up DATA bus 227 b. This designallows for efficient use of the input/output pins on processor 227. Inone embodiment, device 210 might be a device that uses a USB interfaceor a device that uses a three-wire serial interface. According to thepresent standard, USB communications require four lines: a power supplyline, a ground line, and two data lines. The current three-wire serial(RS-232) standard requires three lines: transmit data, receive data, andground. A power supply line can also be included with a three-wireserial connection to allow the devices to share power. With anadditional power supply line, the USB connection and the serialconnection can both include four wires. In this case, no lines of DATAbus 227 b would go unused regardless of the interface. In otherembodiments, one interface could use less lines than another interfaceand some lines of DATA bus 227 b could go unused for certain interfaces.

It is contemplated that processor 227 can reconfigure elements of device220 not only in order to use a communication interface but also for theprocessing of data associated with that interface. For example, ifInterface X is typically used to communicate with a microphone (notshown) then processor 227 can configure circuitry to communicate usingInterface X and to further process voice data. In one embodiment,processor 227 can reprogram an FPGA in device 220 according to data fromINT_SEL 224.

FIG. 3 includes another embodiment of a system 300 operable to select acommunication interface in accordance with the principles of the presentinvention. System 300 can include device 310 and device 320. Device 320can include detector 322, switch 325, input multiplexer (MUX1) 328 a,interface controllers 329 a-329 c, output multiplexer (MUX2) 328 b, andprocessor 327. From one or more measured characteristics, detector 322can be operable to select the communication interface being used bydevice 310. Once an appropriate communication interface is selected,multiplexers 328 a and 328 b can route DATA 310 c through one of theinterface controllers 329 a-329 c in order to facilitate communicationbetween device 310 and device 320. Interface controllers 329 a-329 c canbe circuits operable to coordinate communication between device 310 andcircuitry in device 320 (e.g. processor 327, etc.). Interfacecontrollers 329 a-329 c can be integrated into one or more ASICs. It isalso contemplated that more than three interface controllers can be usedif needed.

The input of MUX1 328 a can be coupled to DATA 310 c and other linesthat are part of the connection between devices 310 and 320. MUX1 328 acan be controlled by detector 322 through EN 323 and INT_SEL 324. EN 323can be coupled to the enable line of MUX1 328 a. INT_SEL 324 can becoupled to the select line of MUX1 328 a. Each interface controller 329a-329 c can be coupled to a different set of MUX1's 328 a outputs.

Once detector 322 selects which communication interface device 310 isgoing to use, detector 322 can direct MUX1 328 a to route its input tothe corresponding interface controller with INT_SEL 324. It iscontemplated that interface controllers 329 a-329 c can be powered offby default, and the appropriate controller can be turned on by a signalfrom detector 322. The outputs of interface controllers 329 a-329 c canbe coupled with the inputs of MUX2 328 b. INT_SEL 324 can be coupled tothe select line of MUX2 328 b. INT_SEL 324 can control MUX2 328 b inorder to connect the outputs from the appropriate controller to acommunication bus (DATA) 327 a of processor 327. Once connected, theappropriate interface controller can initialize communications withdevice 310. What this means is that, an interface controller may takecertain steps, commonly called a “handshake” procedure, to begincommunicating with device 310. These handshake procedures can bedifferent for each type of interface.

Once MUX1 328 a, interface controllers 329 a-329 c, and MUX2 328 b areproperly configured, detector 322 can use EN 323 to close switch 325 andenable MUX1 328 a. In this embodiment, enabling MUX1 328 a correspondsto closing switch 225 of the embodiment in FIG. 2. Once MUX1 328 a isenabled, DATA 310 c can be routed through one of interface controllers329 a-329 c according to the selected interface. Each interfacecontroller can be designed to process a different interface and cansubsequently transmit that data to processor 327. Interface controllers329 a-329 c can be operable to process signals transmitted both to andfrom processor 327. It is contemplated that in order to facilitatecommunicating with processor 327, the interface controllers can beconnected to the same clock signal as processor 327. This clock signalcan be used to coordinate the timing of the communications between theinterface controllers 329 a-329 c and the processor 327.

A person skilled in the art will appreciate that selecting communicationinterfaces in accordance with the principles of the present inventioncan be practiced by other than the described embodiments, which arepresented for purposes of illustration rather than of limitation. Forexample, a system which routes lines to independent subsystems dependingon the selected interface is another embodiment operable to function inaccordance with the principles of the present invention.

FIG. 4 includes an embodiment of system 400 operable to determineconnector orientation in accordance with the principles of the presentinvention. System 400 can include device 410 and device 420. Device 410can include connector 411, and device 420 can include connector 421.Devices 410 and 420 can be coupled by mating connectors 411 and 421.Mating connectors 411 and 421 can connect power supply lines, databusses, and other types of signals between devices 410 and 420. Matingconnectors 411 and 421 can include coupling contacts for two or morephysical connections between device 410 and device 420 even though onlytwo are shown in FIG. 4. Connectors 411 and 421 can be symmetrical sothat connectors 411 and 421 can be mated in two possible differentphysical orientations.

Legend 490 lists two possible physical connector orientations. InOrientation 1, line X1 421 a can be connected to D1 410 a and line X2421 b can be connected to line D2 410 b. In Orientation 2, line X1 421 acan be connected to D2 410 b and line X2 421 b can be connected to D1410 a. The actual physical orientation of the connectors can bedetermined by detector 422 in device 420.

Device 420 can include detector 422 which can be coupled to lines 421 aand 421 b. From one or more measured characteristics, detector 422 canbe operable to determine the physical orientation of connector 411 withrespect to connector 421. Detector 422 can, for example, measure thevoltage of line X1 421 a with respect to line X2 421 b. In this example,the measured voltage can be used to determine whether connectors 411 and421 are in a first or second physical orientation with respect to eachother. Device 420 can include switch 425. Switch 425 can be operable toexist in one of three states: open, connecting its inputs to a first setof outputs, and connecting its inputs to a second set of outputs. Thefirst outputs can be connected to input/output lines of processor 427 sothat X1 421 a can be connected to D1 427 a and X2 421 b can be connectedto D2 427 b. The second outputs can be connected to processor 427 sothat X1 421 a can be connected to D2 427 b and X2 421 b can be connectedto D1 427 a.

Switch 425 can be coupled with detector 422. Before the physicalorientation of connector 411 is determined, switch 425 can be in an openposition so that any circuits in device 420 do not affect themeasurements made by detector 422. Once the orientation has beendetermined, detector 422 can signal switch 425 with a configurationsignal (CONF) 424. Switch 425 can then connect the lines from device 410to circuitry in device 420 according to the physical orientation betweenthe connectors. For example, switch 425 can go to a first position whichconnects X1 421 a with D1 427 a and X2 421 b with D2 427 b ifOrientation 1 is detected. If Orientation 2 is detected, switch 425 cango to a second position which connects X1 421 a with D2 427 b and X2with D1 427 a.

FIG. 5 includes an embodiment of system 500 operable to determine thephysical connector orientation in accordance with the principles of thepresent invention. System 500 can include device 510 and device 520.Device 510 can include connector 511, and device 520 can includeconnector 521. Devices 510 and 520 can be coupled by mating connectors511 and 521. Mating connectors 511 and 521 can include connectingcontacts for three lines between device 510 and device 520. Connectors511 and 521 can be symmetrical so that connectors 511 and 521 can beconnected in two possible orientations. Legend 590 shows two possiblephysical orientations of connector 511 with respect to 521. If there arean odd number of lines coupled between device 510 and device 520, amiddle contact can be connected to the same signal in either connectionorientation. For example, X2 521 b can be connected to D2 510 bregardless of connector orientation. Detector 522 measures one or moreelectrical characteristic of one or more of lines 521 a-521 c in orderto determined whether connector 511 is in Orientation 1 or Orientation2.

Once the orientation of connector 511 is determined, detector 522 canuse configuration signal (CONF) 524 to trigger switch 525 to connect itsoutputs to the appropriate inputs of processor 527. In an embodimentwhere there are an odd number of contacts, a switch coupled with amiddle line can have only an open and a closed position.

It is contemplated that connectors 511 and 521 can have a triangularshape enabling three different coupling orientations. In this case,device 520 can have switches capable of routing the lines from connector521 to the proper lines within device 520. For example, the switches canhave four possible positions which include an open position andindividual positions for each connector orientation.

FIG. 6 includes an embodiment of system 600 operable to determineconnector orientation in accordance with the principles of the presentinvention. System 600 can include device 610 and device 620. Connectors611 and 621 can be symmetrical so that two different matingconfigurations are possible. The connection between device 610 anddevice 620 can include four lines: a voltage line (V_(BUS)) 610 a, afirst data line (D1) 610 b, a second data line (D2) 610 c, and groundline (GND) 610 d.

Two signals can be located on opposite contacts of the connection sothat a line coming into device 620 is known to be one of those twosignals. Legend 690 shows two possible physical orientations ofconnector 611 with respect to connector 621. For example, X1 621 a isV_(BUS) 610 a in Orientation 1 and GND 610 d in Orientation 2. In thisexample, there is no possibility that X1 621 a is D1 610 b or D2 610 c.According to this same principle, a pair of lines can be known tocontain two signals regardless of the connector orientation. Forexample, V_(BUS) 610 a and GND 610 d can be connected to either X1 621 aor X4 621 d, but not to X2 621 b or X3 621 c, regardless of connectororientation.

Device 620 can include voltage regulator 626 and processor 627. A pairof lines which include V_(BUS) 610 a and GND 610 d can be coupled withthe inputs of switch 625 b. The outputs of switch 625 b can be coupledwith voltage regulator 626. The pair of lines which include D1 610 b andD2 610 c can be coupled with the inputs of switch 625 a, and the outputsof switch 625 a can be coupled with the inputs of processor 627.

Detector 622 can be operable to measure one or more electricalcharacteristic of one or more of lines 621 a-621 d. From the one or moremeasured characteristic, the orientation of connector 611 with respectto connector 621 can be determined. Detector 622 can control switches625 a and 625 b using configuration signal (CONF) 624 so that theswitches make the proper connections corresponding to the detectedorientation. For example, detector 622 can measure the voltage on lineX1 621 a and can find it to be consistent with the expected voltage ofV_(BUS) 610 a. In this case, detector 622 can direct switches 625 a and625 b to move to a position corresponding to Orientation 1. Withswitches 625 a and 625 b in this configuration, line 621 a can be routedto V_(BUS) 626 a, line 621 b can be routed to D1 627 a, line 621 c canbe routed to D2 627 b, and line 621 d can be routed to GND 626 b. Notethat by measuring as few as one line which is indicative of theconnectors' orientation, detector 622 can determine how to route all ofthe lines included in the connection.

It is contemplated that connectors 611 and 621 can be designed so thatthere are more than two possible connector mating orientations. Forexample, four contacts arranged so that each contact is a corner of asquare would facilitate a connector that is capable of four differentorientations. In a case where there are more than two possibleorientations, it can not be correct to assume that a signal is found inone of two lines. In accordance with the principles of the presentinvention, switches with a different position for each orientation canbe used in that situation.

A person skilled in the art will appreciate that determining connectororientation in accordance with the principles of the present inventioncan be practiced by other than the described embodiments, which arepresented for purposes of illustration rather than of limitation. Forexample, a system which reconfigures a processor to compensate forconnector orientation is another embodiment operable to function inaccordance with the principles of the present invention.

FIG. 7 includes an embodiment of system 700 operable to determineconnector orientations and select communication interfaces in accordancewith the principles of the present invention. System 700 can includedevice 710 and device 720. Connectors 711 and 721 can be symmetrical sothat two or more different mating configurations are possible. Legend790 shows two possible physical orientations of connector 711 withrespect to connector 721. Device 720 can be capable of communicatingusing different interfaces. In this embodiment, there can be a matrix ofconnector orientations and communication interfaces which define theconnection between device 710 and device 720. What this means is that,in this example, two possible communication interfaces can be used ineither Orientation 1 or Orientation 2. When determining connectororientation and selecting a communication interface, as in theembodiment shown in FIG. 7, there can be four possible configurations.

Device 720 can include detector 722 which is capable of determining theorientation of connector 711 with respect to connector 721 and selectingthe communication interface compatible with device 710. Detector 722 cancontrol switches 725 a and 725 b using configuration signal (CONF) 724in order to configure device 720 for the detected connector orientation.Detector 722 can transmit an interface select signal (INT_SEL) 723 toprocessor 727 that identifies the communication interface used by device710. Processor 727 can subsequently configure itself or other circuitsin device 720 in order to communicate via the detected interface.

It is contemplated that detector 722 can make two different measurementsin order to determine the connector orientation and select theappropriate communication interface. For example, detector 722 mayinclude some inputs coupled to connection lines 721 a-721 d to the leftof switches 725 a-725 b and other inputs connected to lines 727 a-727 band 726 a-726 b to the right of switches 725 a-725 b. In thisembodiment, detector 722 may use one criteria to determine the connectororientation before switches 725 a-725 b close. Subsequently, detector722 may use another criteria to select the appropriate communicationinterface after switches 725 a-725 b have closed to the proper positionwhich compensates for connector orientation.

A person skilled in the art will appreciate that the present inventioncan be practiced by other than the described embodiments, which arepresented for purposes of illustration rather than of limitation. Forexample, a system which routes signals differently to compensate forboth connector orientation and communication interface is anotherembodiment operable to function in accordance with the principles of thepresent invention.

FIG. 8 is a simplified diagram 800 of voltage ranges measured bydetector 722 and the corresponding interfaces and connectororientations. The measurement represented in diagram 800 is the voltageof line X1 with respect to line X3. Diagram 800 is illustrative of theembodiment where two possible communication interfaces, USB andthree-wire serial, are used in combination with two possible connectororientations, but other implementations are possible that will stillutilize the principles of the present invention.

The current USB standard calls for a power supply line with a voltagebetween 4.35V and 5.25V. Therefore range 802, which corresponds to adetected USB interface, extends from 4.0V to 5.5V. Range 804 includesthe same range converted to negative voltages because it corresponds toa USB interface when the connectors are coupled in an oppositeorientation.

Because the three-wire serial standard does not require a power supplyline, the voltage of an optional power supply line can be designed to bedifferent from the voltages of USB power supply lines. For example, thepower supply line can be designed to have a voltage of 3.0V. In thisembodiment, range 806 can extend from 2.0V to 4.0V and correspond to adetected serial interface. Range 808, which extends from −4.0V to −2.0V,can correspond to the same serial interface but with the connectorscoupled in an opposite orientation.

Ranges 810, 812, and 814 can correspond to improperly coupled orunsupported connectors. In other embodiments, additional communicationinterfaces or connector orientations could correspond to ranges 810,812, and 814.

FIG. 9 shows a flowchart of process 900 which can be implemented toselect appropriate communication interfaces in accordance with theprinciples of the present invention. At step 910, two devices can becoupled by mating two connectors. This connection can include one ormore electrical contacts. At step 920, one of the devices can measureone or more electrical characteristic of the connection. The electricalcharacteristic can include a resistive, reactive, current, or voltagemeasurement and can involve one or more contacts. In one embodiment, themeasurement can be of the voltage of one contact with respect to anothercontact. In an alternative embodiment, the measurement can be of theresistance between two contacts.

Step 930 in process 900 depends on the measurement obtained at step 920.If the measurement is within a certain predetermined range, process 900can continue with step 940. If the measurement is within a differentpredetermined range, process 900 can continue with step 950. If themeasurement is within a third predetermined range, process 900 cancontinue with step 960. Each different range can correspond to ameasurement that would be expected for a different communicationinterface. The number of different branches of process 900 can bedefined by the number of interfaces a device can use to communicate.

In one embodiment, process 900 can repeat step 920 if the measurementdoes not fall into any of the predetermined ranges (not shown). Inanother embodiment, process 900 can resolve that same situation byprompting a user (not shown). The user prompt could, for example,request that the user check the connection or allow the user to selectthe interface type.

At step 940, 950 or 960, the device which performed the measurement canbegin to use a predetermined communication interface which correspondsto the value of the measured characteristic. In order to use theselected interface, the device can load a corresponding set ofinstructions onto a processor. In an alternative embodiment, the devicecan route the signals to the corresponding circuits or ICs for eachinterface.

FIG. 10 shows a flowchart of process 1000 which can be implemented todetermine connector orientations in accordance with the principles ofthe present invention. At step 1010, two devices can be coupled bymating two connectors. The connectors used can be designed so that theycan fit together in more than one physical orientation. At step 1020,one of the devices can measure an electrical characteristic of theconnection.

At step 1030, process 1000 can proceed differently depending on thevalue of the measured characteristic. If the measured characteristic iswithin a predetermined range, process 1000 can proceed with step 1040.At step 1040, a device can route the connected lines to pathscorresponding to Range A. If the measured characteristic is within asecond range, process 1000 can proceed with step 1050. At step 1050, theconnected lines can be routed to paths corresponding to Range B. Theranges can be selected so as to differentiate between possible connectororientations. For example, a device can measure the voltage of a linethat is expected to be either a power supply line or ground depending onthe physical orientation of the connectors. In this example, twopossible voltage ranges can be separated at a value that is in betweenthe expected supply voltage and ground.

FIG. 11 shows a flowchart of process 1100 which can be implemented todetermine connector orientations and select appropriate communicationinterfaces in accordance with the principles of the present invention.At step 1110, two devices can be coupled by mating two connectors. Theconnectors used can be designed so that they can fit together in morethan one physical orientation. At step 1120, one of the devices canmeasure an electrical characteristic of the connection. At step 1130,process 1100 diverges. Depending on the characteristic measured at step1120, process 1100 can proceed with step 1140 or step 1150. Step 1140can correspond to routing connection lines in accordance with oneconnector orientation and step 1150 can correspond to routing connectionlines according to another connector orientation. It is contemplatedthat more than two connector orientations can be used in accordance withthe principles of the present invention.

At step 1160 a device can measure one or more electrical characteristic.The measured characteristic can be used to select the communicationinterface appropriate for the two devices to use when communicating witheach other. It is also contemplated that, instead of making a newmeasurement, the measurement generated at step 1120 can be used toselect an appropriate communication interface at step 1170 withoutdeparting from the spirit of the present invention. Depending on therange of the measured characteristic, process 1100 can proceed with step1180 or step 1190. At step 1180, the devices can communicate usingInterface X. At step 1190, the devices can communicate using InterfaceY. In order to communicate using the appropriate interface, a devicecan, for example, route the connection lines to the proper circuitry forthat interface. Alternatively, a device can load a set of instructionsspecialized for communicating with the appropriate interface.

Thus it is seen that descriptions of systems and methods for determiningconnector orientations and selecting communication interfaces areprovided. A person skilled in the art will appreciate that the presentinvention may be practiced by other than the described embodiments,which are presented for purposes of illustration rather than oflimitation.

1. A method of selecting a serial communication interface comprising:connecting a plurality of lines between a first device and a seconddevice; electrically coupling only a subset of the plurality of lines tocircuitry within the second device; measuring a characteristic of atleast one line in the subset of the plurality of lines; selecting anappropriate serial communication interface based on the measuredcharacteristic; configuring the second device so that it is operable tocommunicate using the selected serial communication interface, whereinconfiguring the second device comprises configuring a processor in thesecond device; and electrically coupling all of the plurality of linesto circuitry in the second device after the selecting.
 2. The method ofclaim 1 wherein the measured characteristic is voltage.
 3. The method ofclaim 1 wherein the selected serial communication interface is aUniversal Serial Bus interface.
 4. The method of claim 1 wherein theselected serial communication interface is an RS-232 serial interface.5. The method of claim 1 wherein configuring the second devicecomprises: routing lines between the first device and the second deviceaccording to the selected serial communication interface.
 6. The methodof claim 5 wherein the lines from the first device are routed toinput/output lines of a processor in the second device which is operableto process the selected serial communication interface.
 7. The method ofclaim 5 wherein the lines from the first device are routed to circuitryoperable to process the selected serial communication interface.
 8. Amethod of determining the physical orientation of two connectors withrespect to each other comprising: connecting a first device to a seconddevice by physically coupling a first connector to a second connector,wherein the connectors are capable of being coupled together in morethan one physical orientation, and wherein connecting compriseselectrically coupling a subset of a plurality of lines between the firstand second devices, the subset being just the lines necessary to measurea characteristic of at least one line in the connection between thefirst connector and the second connector; measuring the characteristic;determining the physical orientation of the first connector with respectto the second connector based on the measured characteristic; androuting lines from the first device to the second device based on thedetermined physical orientation.
 9. The method of claim 8 wherein themeasured characteristic is voltage.
 10. The method of claim 8 whereinthe connectors comprise an odd number of lines and connecting comprisesrouting one of the lines between the first device and the second devicethe same way regardless of the determined physical orientation.
 11. Amethod of determining the physical orientation of two connectors withrespect to each other and selecting a serial communication interfacecomprising: connecting a first device to a second device by physicallycoupling a first connector to a second connector, wherein the connectorsare capable of being coupled together in more than one physicalorientation, and wherein connecting comprises electrically coupling asubset of a plurality of lines between the first and second devices, thesubset being just the lines necessary to measure a characteristic of atleast one line in the connection between the first connector and thesecond connector; measuring the characteristic; determining the physicalorientation of the first connector with respect to the second connectorbased on the measured characteristic; selecting an appropriate serialcommunication interface based on the measured characteristic;configuring the second device so that it is operable to communicateusing the selected serial communication interface, wherein configuringthe second device comprises configuring a processor in the seconddevice; and routing lines from the first device to appropriate lines inthe second device based on the determined physical orientation.
 12. Themethod of claim 11 wherein the measured characteristic is voltagepotential.
 13. The method of claim 11 further comprising: measuring asecond characteristic of at least one line in the connection between thefirst connector and the second connector.
 14. The method of claim 13wherein the second measured characteristic is used to select anappropriate serial communication interface.
 15. The method of claim 11wherein the selected serial communication interface is a UniversalSerial Bus interface.
 16. The method of claim 11 wherein the selectedserial communication interface is an RS-232 serial interface.
 17. Themethod of claim 11 wherein configuring the second device comprises:routing lines between the first device and the second device accordingto the selected serial communication interface.
 18. The method of claim17 wherein the lines from the first device are routed to input/outputlines of a processor in the second device which is operable to processthe selected serial communication interface.
 19. The method of claim 17wherein the lines from the first device are routed to circuitry operableto process the selected serial communication interface.
 20. An apparatusfor selecting a serial communication interface comprising: a connectorfor coupling the apparatus with another device; one or more contacts forphysically connecting lines between the apparatus and the other device;detector circuitry for measuring an electrical characteristic of atleast one of the one or more contacts; switch circuitry operable toconnect at least one of the one or more contacts to other circuitry inone or more configurations; control circuitry operable to interface thedetector circuitry with the switch circuitry, wherein the detectorcircuitry selects a serial communication interface based on the measuredcharacteristic and the control circuitry instructs the switch circuitryto configure itself accordingly; and a processor that is electricallycoupled with the control circuitry, wherein the control circuitryinstructs the processor to configure itself based on the selected serialcommunication interface.
 21. The apparatus of claim 20 wherein themeasured characteristic is voltage.
 22. The apparatus of claim 20wherein the measured characteristic is resistance.
 23. An apparatus fordetermining the physical orientation of a connector comprising: aconnector for coupling the apparatus with another device; one or morecontacts for physically connecting lines between the apparatus and theother device; detector circuitry for measuring an electricalcharacteristic of at least one of the one or more contacts; switchcircuitry operable to connect at least one of the one or more contactsto other circuitry in one or more configurations; control circuitryoperable to interface the detector circuitry with the switch circuitry,wherein the detector circuitry determines the physical orientation ofthe connector based on the measured characteristic and the controlcircuitry instructs the switch circuitry to configure itselfaccordingly; and a processor that is electrically coupled with thecontrol circuitry, wherein the control circuitry instructs the processorto configure itself based on the determined physical orientation of theconnector.
 24. The apparatus of claim 23 wherein the measuredcharacteristic is voltage.
 25. The apparatus of claim 23 wherein themeasured characteristic is resistance.
 26. An apparatus for determiningthe physical orientation of a serial connector and selecting a serialcommunication interface comprising: a connector for coupling theapparatus with another device; one or more contacts for physicallyconnecting lines between the apparatus and the other device; detectorcircuitry for measuring an electrical characteristic of at least one ofthe one or more contacts; switch circuitry operable to connect at leastone of the one or more contacts to other circuitry in one or moreconfigurations; control circuitry operable to interface the detectorcircuitry with the switch circuitry, wherein the detector circuitrydetermines the physical orientation of the connector and selects aserial communication interface based on the measured characteristic andthe control circuitry instructs the switch circuitry to configure itselfaccordingly; and a processor that is electrically coupled with thecontrol circuitry, wherein the control circuitry instructs the processorto configure itself based on the determined physical orientation of theconnector and the selected serial communication interface.
 27. Theapparatus of claim 26 wherein the measured characteristic is voltage.28. The apparatus of claim 26 wherein the measured characteristic isresistance.